The 39-year-old actor portrays notorious stockbroker Jordan Belfort in the movie, and he was advised by the banker on how to act in a scene where he had to crawl to a car while on drugs - and he found mimicking his moves incredibly painful.

He told the New York Post newspaper: "I didn't know anything about Quaaludes, and he had taken a tremendous amount of them.

"I videotaped him on the floor, rolling around, and he really articulated to me that you have every intention of going to a certain destination, but your body doesn't go along with you. We shot it for, like, a week, and it was a lot of chiropractic work for me because it was incredibly painful."

Meanwhile, Leonardo's co-star Jonah Hill admits he wouldn't use the expletive-filled language of the movie in his everyday life.

He said: "I'm happy to be in Scorsese's movie. I try not to use those phrases at home. But the script's so brutally honest I didn't mind saying them."

And even the movie's director Martin Scorsese admits his language at home is much more moderate.

He said: "I never say them in real life. Maybe if I accidentally cut myself shaving and blood's pouring from my throat, I might utter such a word. Otherwise - never."